1. Field of the Invention
This invention relates to a method for the production of a clay having layers thereof cross-linked with pillars and possessing a cation-exchange capacity and a clay having layers thereof cross-linked with pillars different in kind. The products obtained by this invention can be used such as for catalysts, catalyst carriers, adsorbents, separating materials, and cation-exchangers.
2. Prior Art Statement
The present inventors have been granted U.S. Pat. Nos. 4,629,713, 4,753,908, 4,839,318, 5,087,598, 5,084,428 and No. 5,214,012 on their inventions pertaining to methods for production of minute porous clay particles from a smectite type ore as a raw material.
No method has yet been established for the production of a pillared clay having cation-exchange capacity or a pillared clay having the layers thereof cross-linked with a plurality of kinds of pillars.
The clay which is possessed of silicate layers and has these silicate layers cross-linked with pillars is referred to as an "pillared clay".
A pillared clay contains pores of a size closely approximating the size of molecules. It is in the form of a microporous substance which can be expected to manifest the function of a molecular sieve or the function of a shape selector, depending on the size of the interval between the layers or the size of the interval between the pillars. The pillared clay is synthesized by introducing a cationic pillar precursor into the interstices between the silicate layers of such a smectite ore as montmorillonite or hectorite and establishing pillars between the layers. It is therefore devoid of the cation-exchange capacity inherent to the smectite ore. To be usable as a catalyst carrier or a cation exchangers, however, the inter-layer cross-linked clay is required to possess cation-exchange capacity. Moreover, for imparting it with such functions as catalysis and adsorption, the inter-layer cross-linked clay is required to use a plurality of kinds of pillars. This invention has been perfected to fulfill these requirements.